What is the ruling on learning worldly sciences from a Muslim teacher who jokes, saying: "The two angels will come, so bribe them," and sometimes backbites people?

Learning from this teacher is permissible, but he must be advised when committing a sin, such as backbiting or mockery. If he intends, by his words, to mock the two angels and the questioning in the grave, then this is a grave evil and a great danger. He must be advised by clarifying that such matters should not be a subject of laughter and ridicule.